1. Field of the Invention
This invention lies in the field of valves actuated by stem movements and particularly to combination of such valves with independent removable hermetic external seal means.
2. Description of the Prior Art
In the art of aerosol-type valves, it is common for a reclosable valve assembly to be operated during opening and closing by means of the movement of the valve stem through application thereto of an appropriately applied external force, as from an operator's finger. Typically during operation, such a valve stem is moved or displaced (e.g., tilted or reciprocated) relative to its normally upright closed (typically axially aligned) position.
Especially when the fill of a pressurized container that is functionally associated with such a valve assembly (as the dispensing means) is sensitive to, or reactive with oxygen, water vapor, or other substances found in the atmospheric environment, it would be desirable to seal externally annd hermetically the valve assembly (relative to the fill in the container) until such time as the fill is to be dispensed and used. At such time, it would be desirable to open such seal permanently by means of an externally applied force after which the reclosable valve assembly can be opened and closed in typical fashion for dispensing the fill.
In the prior art, a variety of externally used valve protective cover means have been employed to adjoin a protective member with a valve body. Such mechanical means have included snap or force fits, screw-on arrangements, frictional fits, and the like. One class of such protective cover means comprises so-called tamperproof closures. So far as can be determined, in such prior art, there are no teachings or suggestions of using a separate bonding means to secure a protective cover to a valve for purposes of providing an hermetic seal over and about valve components in combination with a valve body with which the protection cover and bonding means are in gas-tight association. Furthermore, the prior art does not appear to provide such external seal structures which are additionally able to be opened by external force, thereafter to permit normal valve opening and closing operations to proceed to purposes of dispensing the pressurized fill of a valve-associated container.
Thus, so far as is now known, reclosable valve assemblies of the type operatable by valve stem movement have not previously been known which were provided with removable external hermetic seal means wherein a seal member is bonded in a gas-tight manner to a valve body after such valve body is mounted upon a container.
Previously, I have invented a class of reclosable valves operated by valve stem tilting which are provided with an external reclosable valve stem tip seal which is operated by valve stem tilting. This tip seal forms a second seal which protects material possibly retained in the stem from atmospheric action associated with valve stem tilting in a previous use; see Beard U.S. patent application Ser. No. 394,517, filed July 2, 1982, now U.S. Pat. No. 4,418,847, issued Dec. 6, 1983. However, because this tip seal is operated through the existence of an internal force it does not provide a hermetic seal of the class presently provided.